Sierra hits Macs on September 20th with Siri in tow

Sierra, the latest version of macOS (formerly OS X), will be available to download on September 20th. The update adds Siri to the Mac, the ability to copy and paste among Apple devices, and it enables picture-in-picture, which allows users to pop out a video from iTunes or Safari and keep it playing in a separate floating window. Plus, Apple Music has a new, streamlined UI and the Photos app gets an upgrade with a "Memories" view that collects shots taken in specific places or of certain people.

The new operating system updates the messaging app as well, adding enlarged emojis, inline previews of videos and links, and the ability to respond to a message with a heart, thumbs up or other icon.

We gave Sierra a spin in June and found most of its features to be intuitive and handy. However, that was an early build and we weren't able to try out auto-unlock (which opens your Mac from an Apple Watch), Apple Pay on the web and some of the features that work alongside iOS 10.

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